The histone binding capacity of SPT2 controls chromatin structure and function in Metazoa

Histone chaperones control nucleosome density and chromatin structure. In yeast, the H3-H4 chaperone Spt2 controls histone deposition at active genes but its roles in metazoan chromatin structure and organismal physiology are not known. Here we identify the Caenorhabditis elegans ortholog of SPT2 (CeSPT-2) and show that its ability to bind histones H3-H4 is important for germline development and transgenerational epigenetic gene silencing, and that spt-2 null mutants display signatures of a global stress response. Genome-wide profiling showed that CeSPT-2 binds to a range of highly expressed genes, and we find that spt-2 mutants have increased chromatin accessibility at a subset of these loci. We also show that SPT2 influences chromatin structure and controls the levels of soluble and chromatin-bound H3.3 in human cells. Our work reveals roles for SPT2 in controlling chromatin structure and function in Metazoa.</p

The mammalian centrosome and its functional significance

Primarily known for its role as major microtubule organizing center, the centrosome is increasingly being recognized for its functional significance in key cell cycle regulating events. We are now at the beginning of understanding the centrosome’s functional complexities and its major impact on directing complex interactions and signal transduction cascades important for cell cycle regulation. The centrosome orchestrates entry into mitosis, anaphase onset, cytokinesis, G1/S transition, and monitors DNA damage. Recently, the centrosome has also been recognized as major docking station where regulatory complexes accumulate including kinases and phosphatases as well as numerous other cell cycle regulators that utilize the centrosome as platform to coordinate multiple cell cycle-specific functions. Vesicles that are translocated along microtubules to and away from centrosomes may also carry enzymes or substrates that use centrosomes as main docking station. The centrosome’s role in various diseases has been recognized and a wealth of data has been accumulated linking dysfunctional centrosomes to cancer, Alstrom syndrome, various neurological disorders, and others. Centrosome abnormalities and dysfunctions have been associated with several types of infertility. The present review highlights the centrosome’s significant roles in cell cycle events in somatic and reproductive cells and discusses centrosome abnormalities and implications in disease

Smad proteins are targets of transforming growth factor beta1 in immortalised gonadotrophin-releasing hormone releasing neurones

Transforming growth factor beta (TGFbeta) is one of the growth factors involved in the neuroendocrine control of the gonadotrophin-releasing hormone (GnRH) neurones. It is produced and released by the astrocytes surrounding GnRH neurones and directly controls their secretory activity. TGFbeta signalling is based on a complex of two receptors that transduces the signal through peculiar intracellular substrates, the Smad proteins, which, upon activation, move into the nucleus, and modify the transcription of TGFbeta responsive genes. The present study aimed to verify whether TGFbeta1 is able to regulate the Smad pathway in GT1-1 cells (i.e. an immortalised neuronal cell line releasing GnRH). We show that: (i) GT1-1 cells express Smad 2, 3, 4, and 7; (ii) TGFbeta1 enhances the phosphorylation of Smad 2 and 3 at short times of exposure (15-30 min); (iii) TGFbeta1 induces the synthesis of the inhibitory Smad 7 at longer times (60-120-240 min); (iv) the conditioned medium of type 1 astrocytes enhances the phosphorylation of Smad 2 and 3 in GT1-1 cells and a TGFbeta1 neutralising antibody counteracts this effect. The results indicate that Smads are targets of TGFbeta1 and that astrocytes are able to modulate Smads proteins in GT1-1 cells through the release of TGFbeta1. Taken together, the data provide new evidence that glial cells are important regulators of the GnRH neuronal activity

Percutaneous nephrolitotripsy in patients with solitary kidney. Our experience

Percutaneous nephrolitotripsy in patients with solitary kidney. Our experienc

Pretransplant Nephrectomy for Large Polycystic Kidneys in ADPKD (Autosomal Dominant Polycystic Kidney Disease) Patients: Is Peritoneal Dialysis Recovery Possible after Surgery?

The choice of modality for renal replacement therapy in patients with ADPKD varies, often based on patient choice, physician-related factors, and resource availability. For a long time peritoneal dialysis (PD) was considered as relative contraindication due to the possible limited intraperitoneal space. In recent years, some studies suggested it is a valid option also in patients with ADPKD to be considered as a first line treatment in potentially fit patients. Diuresis volume lowering and potential permanent damage of peritoneal integrity, both leading to a necessary switch to haemodialysis, are the two most important dangers after nephrectomy, especially if bilateral, in PD patients. We performed a retrospective analysis of patient underwent native polycystic kidney nephrectomy in order to state the possibility to recover peritoneal dialysis after surgery

Testicular metastasis of signet ring cell tumour of unknown origin: Diagnostic features of a tricky case

We introduce the diagnostic complexity of a testicular metastasis by signet ring cell adenocarcinoma of unknown origin. Testicular metastases are a rare event but, particular after 50 years of age, a testicular mass could represent a metastasis. © 2011 Blackwell Verlag GmbH